Supply of energy to electric-railway systems.



C. H. DOUGLAS.

SUPPLY OF ENERGY T0 ELECTRIC RAILWAY SYSTEMS.

APPLICATION FILED JUNE 25. I915- Patented Dec. 7, 1915.

I r V INVENTOR l a? I Wrnqq WITNESSES. QMM. WW

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CLIFFORD HUGH DOUGLAS, 0F PATGHAM, ENG-LAND.

SUPPLY 0F ENERGY T0 ELECTRIC-RAILWAY SYSTEMS.

i ,itififilet.

Specification of Letters Yatent.

Patented Dec. '7, 1915.

Application filed June 25, 1915. Serial No. 363.8%.

1 b all 1070072). it may concern Be it known that I, Cmrronn Hucn DOUGLAS, a SHbJGCt of the King of Great Britain, and a resident of Patcham, England, have invented a new and useful Improvement in the Supply of Energy to Electrio-Railway Systems, of which the follow ing is a specification.

This invention relates to electric railway systems oi the kind in, which direct current is supplied to an insulated conductor from which it is collected in a known manner by a shoe or collector bow and transmitted to direct current motors on the trains. The ma ning rails are bonded and used for the return current.

Since the system of energy supply of this invention her after described renders the lo cation of: the circuit interrupting devices in the motor circuits equally eiiective whether placed on or off the moving trains the sys tcm is equally applicable to trains with or Without drivers. In the latter case it may be desirable to employ separately excited or compound wound motors in which case an independent conductor may convey the shunt field current, but the system as described is independent of the type of direct current motor employed.

Sections of the conductor rail. or wire which may correspond in length and posi tion to signal block sections are insulated from each other. Treadles of the usual depression, or other known type, operated by the train are placed at or near the entrance of such rail sections and block section switches are placed in the feeder circuits to each of the sections in such a manner that when operatedfhy a. passing train the sec tion behind that occupied is made dead but made alive again on the train passing to the section still farther ahead. It will be understood that in this: way there is one and only one dead section immediately behind each train.

,According to the present invention the pressure appliedto anygiven section is entirely controlled at any given time by a. generator, installed in the manner hereafter indicated and connected to the saidsection in a manner hereinafter describediby way of example. The pressure of this generator is determined by. the resistance interposed in itsfield circuit and the amount of this interposed resistance s su tably controlled by an automatic regulatingdevice set in motion by the current taken by the train. The well known potentiometer connection type of field resistance may advantageously be employed. This operation may be further controlled by any diii'erence of pressure between two sections not to be supplied from the same sub-station as hereinafter described or in addition the motion of the field rheostat comprising such resistance may be arrested by limit switches designed in a known manner to prevent the current due to the pressure from rising beyond a predetermined amount.

In the example herein described and illustrated in the accompanying drawing, the generator forms part of a motor generator set consisting of two generators and one motor which latter is not shown and may be of any, convenient type. Each generator will have a suitable maximum pressure approximately equal to that required by the train motors when running at full speed. Said generator will normally be driven at a constant speed by its motor and (when not supplying current) be excited to such a degree.

as will suffice to produce the full accelerating current through the train motors when at rest. On the closing of the circuit between the generator and the train motors, such closing being performed by a switch either on the train or elsewhere, and assuming that the circuit is not further interrupted by the block section switche-spreviously referred to, the train will start. By the action of a relay operated by the current supplied to the. motors, the circuit to the operating mechanism of the field rheostat will be closed and the rheostat will operate, raising the pressure at a predetermined rate and accelerating the train.

In the system of my invention each train is started and driven over adistance limited only by the economic radius of energy distribution at the pressure employed, by current produced by one generator which at. any one time is only supplying current to a single train. No resistance need be inserted or cut out from the main motor circuit when the speed is tobe altered; the conductor rails are kept at the potential required under the existing conditions irrespective of the load on the train or. the number of units constituting the train and the waste of energy in the controlling resistances is greatly lessened and the connections simplified.

In order that two or more trains may be tion just left, dead, and the penultimate section 'alive again, it also throws over a twoway swltch so that when the section ust left is made alive agam said section is connected to a generator other than thatwhich was associated with the said passing train. If two or more trains are torun at the same time between two distributing stations, the multiway switches must provide for the connection, to the section behind any given train, of each generator of the number required, in rotation.

'The'system of supplying energy to the moving trains of this, invention differs 'essentially from that of the well known contact stud or similar systems. In the latter all the studs or insulated sections from which the moving train obtains its propulsion current are normally dead and such studs or insulated sections are energized I and enable the moving traln to receive ourrenttherefrom'by its passage over and contact withthem. In the'present 1nvent1on all the insulated sectlons of the conductor rail 7 or trolley Wire except that section immediately behind a train are at all times energized, that is to say are in direct connection with a generator or generators and therefore the usual pick up coils or devices provided for'energizing the conducting studs or sections hitherto employed are dispensed with. I

It is to be noticed that according to this invention (a) the conductor rail is by the connections employed as regards one area of distribution, that is to say the sections energized from one sub-station, electrically continuous in front of a train up to the point where it is blocked by a preceding train (1)) none of'the switches employed are required to operate when current is flowing through them (.0) any failure of a treadle merely blocks the train behind it. v

In order that the nature of the invention may be clearly ascertained, it will now be described with reference to the accompanying drawing which shows diagrammatically by waylof example, but not of limitation, one arrangement of they circuits .and the various switches together with the means whereby the same are operated at the ap proprlate times. j

Referring to the drawing, S S S S S are the clock sections of the insulated conductor of which the first three are supplied from sub-station A and the two latter from sub-statlon B. The running rails, bonded together, which form the return circuit, are indicated at N. i

The train motors and their circuits are shown in the drawing at Maud form a movfing connection between N and S S etc.

The circuits conveying current from the several generators to the motors on the train are shown in heavy lines while the circuits for operating the various switches, rheostats, and so forth are shown in thin lines.

Two generators (6 and b are shown at substation A and two generators 0 and d at substation 13. The generators at each sub-station are arranged to be driven at a substantially constant speed by a motor (not shown). The actuating coils operating the various switches, relays, and the automatic rheostats are energized'from a battery a? one pole of which is connected to the earth-v return N and the otherpole is connected to a battery wire 10. Automatically operated rheostats R E- R R are included in the circuits of the fieldmagnet windings (i Z2 0 d respectively of the generators a,'b, 0, (Z. In the position shown .in the drawing all the resistance of each of the rheostats R R R Ris in circuit with its respective field winding b c or (P. The rheostats R RF, R ll are adapted to be operated automatically by means of polarized relays, solenoids, or by any suitable means in the manner. hereinafter pointed out in conjunction with a. dash pot y or equivalent device whereby the rate at which the rheostat cuts out resistance can be adjusted as desired.

One pole of each of the generators at, b, c,

(Z is respectively connected to one of the bus bars B? B B B the other poles of the gen-. erators being earthed as shown. Feeder circuits F F F leading respectively from the insulated sections S S S are adapted to be connected with one or other of the. bus bars B or B by means of the two-way switches LS LS L S and similar feeders F F respectively connect the insulated secti ons S S 't'o one or other of the bus bars 13 or B through two-way switches LS LS Solenoid operated block sectio-nfswitches MS MS? MS MS and MS are provided for opening and closing the feeder circuits F F F F? F respectively. Two-way switches TS. and TS? respectively mechanically linked with the switches LS and LS the resistance of the rheostats R R 351? in their respective field windings will tie liver a pressure to theinsulated sections S S ctcg, only suili'cient to produce the necessary accoleating current through the train motorswhen at rest; c I

The systemshown in the drawing is in thecondition' in which it was left by a train which. has passed over the-whole of the sections S 8 etc, and'was propelled bygenerator (1/; as far as section and by gene-rator (3 over sections and S and is at,pres cut on the nex succeeding section beyond section 5 (not shown); The succeeding train or now uncerconsideration is on section S andassuinedto be traveling from left to rightof the diagram, and with the various switches in the-positions indicated in the diagram the trai'nm'zi will receive cur rent from the generator through .the bus bar B thence through the switches LS and ll [S and the insulated section S the switch II being closed; Current will also How fromthe other terminal of the genera tor 5 through the coil as tofearth which will close the switch The closure of this by establishing a circuit from earth through coil 2 of switch M8 battery wire lOand the battery to earth. This will cause i switch M5 to be thrown to the open position, thus cutting off the supply of current to theinsulated section S from the generator 7) which operation thus renders sect-ion S dead Current will also flow from earth at treadle T coil 2 of switch LS battery wire 10 and battery-a to earth at N which will-throw the switch LS to the right. This will connect generator a through the bus bar B with the-feeder F so that when the switch MS v again closed the next train entering section S "ill be operated by generator (1. lVhen the train reaches the entrance to insulatedsection S,

the treadle T will be depressed and a circuit through coil 2 of the switch MS isina de in a similar manner to that alreadydescribed when the treadle T was depressed. In addition a circuit will also be made from earth through treadleT and coil 1 of switchMS battery wire 10' and battery so to earth. The coil will thereby be energized and the switch MS again closed, thus energizing the block section S from generator at as above described, section S being at the same time rendered dead by the opening ofthe switch MS? The depression oitreadl'e T also completes a circuit through will "of" switch thereby insuring closure'of this switch. closure of switch PS completesa circuit from the energized section S through'l the s itch T3 and coil. CB or CB ofone or other of theauto'inatlc rheo'stats B R* de ending on the position of the hnked switches TS? and LS, which determine whether the generator 0 or the generator d, will supply current to the train, and thenceto the feeder F enerator 0 0rd to the ground. In the position of the switches shown in the diagram the generator 0 will be connected to the insulated section S through the bus bar B, switches LS and MS. The

auton'iatic rheostat R willbe operated by the solenoid CB to cut out resistance iroin the field circuit 0 of the generator 0 which will 'oonsec'piently attain the same potential asflthat of the insulated section S so that sections 5 and tential. l

The coilsCB and CB and the associated plungers .:=perating the rheostats :R R

are merely diagranunatic. In practice the means for operating the rheo'stats are such that the direction of motion of the rheostats is dependentupon the direction of flow of the current through said coils. 'In this way a current flowing through coil CB of rheostat R from section S to section S", or through 0011 GB of 'rheostat R according to the position of the switch TS' fromseC- tion 8* to section 8* will cause the rheostats tooperate soas to cutresistance out of the iields of their respective generators. Conwill beat the same p'o' i versely if the current through either ofthese coils hows from section ,S to section 1 S the automatic rheo-stat'R or R will be operated in the reverse direction and resistance will be cut into the fields of the generator c or d. In thisway the potential o-fthe" 'sectionstffl", S andS may be made approximately equal although supplied from sepa- Similarly the coils or rate sub-stations. polarized relays CB andCB operate the rheostats R and R in a similar way so that a current flowing through these coils in one direction from adjacent insulated sections will cause the rheostatsto operate to cut re sistance out of the fields a b of the respective generators at Z) Whilecurrent flowing" through coils CB and GB in the'op'pos te direction will cause the rheostats R and R to cut resistance lnto said field windings.

As the train proceeds from sectionv S to section 8* the treadle T is depressed and connections are thereby made from earth through coil 2 of switch MS opening said switch and through coil 2 of switch PS thereby opening the same and through coil 2 of switch LS thereby throwlng over switch LS and connecting generator at I through bus bar '13 with-switch so that no longer deliver current, and consequently *fswitch 'p willibeopened and the pressure of.

generator?) willgfall to its initial pressure. ,owingto the rheostat R returningto the wherithisjswitch is neXt closed the followin train tothat the rocession oi which is now .b81I1 described will-receive ener Y b 7 22 while onsejctio'ns S S or Stfrbnr generator a and not from generator bwhich furnished energy to the trainlunder considerationg The opening of switch PS deprives coilCB? ofrheostatR; of current, butthe pressure of the generator c will'lbe' maintained owing 1 j to thej closing of switch p? by the current to the train; As the feeder F is opened by theopening oif 'swi tclrMS generator I) will positionii'n which all of its'resistance is again out into the field" Z2 due to c1rcu1t or th'e coil (W2 'haying 'been opened by switch w, The train having enteredfsection S ,7 anchthe" switch LS being in the position i 7 shown; CHIIBIliZ'; 'W1ll, as stated above, be

' WllGIljllllS block is releasedbythe preceding, trail-ins similar to that already described:

delivered to the trainon this section froin rtl'iegeneratorlc; bus bar B, switch LS and feeder F As shown, section S is'blockcd by. a precedingv train and'theinrther pro cession of "the train under considerat on To. operate-trains on asingle line in either direction additional -treadles niust'be pro- 1 ided atthe'ientrance toceach section considered with respect tothe dlrect on of mot on I of the train;

nients fordepressing the samemust besuch that only those treadles appropriate to the direction ofrmoveinent of the train will be operated. In the caseof a doubleline the arrangements herein ljdescribcd will be =duplic ated.

Thetrains shown inthe accompanying dr wing and hereinabove described are adapted tobe'operated by a motorrnan-located on the; train bythe ni'a-nipulation of the switch K. 71i illlfirbi'tlllSfil-l'filli) be'propelled without dr vers manually operated switches actuated .by a switchinan or train despaitcher.

will be included in the feeders at the stations. f 1

,,Whi1e 171m described two generating sub stations A and B each providedwith two generators, I wish] it understood that only a single sub-station may beused oral g i 1 31 than two, and more than two generators inleach sub-station if necessary,,depending upon the length of line and 1 other conditions well understood by elec A cal engineers: i

As hereinabove described the provision of two generators at each sub-stat1on,- and the provision of tWo-waysyvitches between-the bus bars to which they are connected and the feeders of theiinsulated section enable two trains "to be operated automatically The, trcadles and arrange each by its own generator at th'ev same time in the area fdistribution seryed by a substation. In order that inore than twotrains; may be runnlngiat theisam'e'tnne 1n the same direction withinthe areaof distribu I tion' served by a single snb-station,;gener i ators and switches, with manydiiierent' positions as there are trainsto be snnultaneously driven must be providedlfor connect ing the feeders in tu with the respective busbarfs ofeach of the generators of; which eac'htrain. 1

c a mas my lnv iltion'z g 1. In anelectrically operatedrailway sys-V teni the conibinationwith asupply-conductor divided into insulated sections and a generator 1 foreach section f for supplylng electricenergy theretori'of means "set n inc tion by the current taken bya train in one one 'iiiust be rovided to sun l ener to" section for varyingethe potential' ottheg generator feeding the succeeding section.

In an electrically operated'railway sys t nure combination with a conductor rail; divid'ed'into insulated sections and a genera-tor for each sect-ion for. supplyiiig'elcctric "energygthereto, of means set ininotion by a the current taken-by train in one section foryarying theresistance in the field circuit oit thegenerator for supplying energy to the succeedingsection.- i

, In an electrically operated railway. sys 'tein the combination with a contact c'onductor divided into insulated sections and a .7 generator :for each section for supplying a electric energy "thereto of Vrheostatsone for varyingthe ainountof resistance in the field circuit of each' generatorand meanswfor automatically operating the rheostat of, one

field circuit when thetra-in is in a preceding section, sald means beingcontrolled by the current taken by the train.

4. In an electrically; operated railway sys r tein the combinationwith a supply conductor divided into insulated sections,'of a plurality of generators for supplying-energy-"thereto "and switching devices: con-V trolled by the p'assage of -thetrain for connecting one of said generators at aztiine" to l the insulated: sections of the supply con-' ductor in'succession and fordisconnecting each of'said sejctionsfroin'said generator after thetrain has passed toa-succeedmg 7 section. b 1 ln'an'electrioally operated railway system the combination with a conductorvr ail' divided into insulated sections and a plusaid sections from said generators after the passage of a train thereoyer.

6. In an electrically operated railway systern the combination of a supply conductor divided into insulated sections, a plurality of generators for supplying energy thereto, automatically operated switches controlled by the passage of the train for connecting and disconnecting said generators from the insulated conductor sections and automati cally operated switches also controlled by the passage of the train for selecting one of said generators to supply energy to each train during its passage over the whole of said insulated conductor sections.

7. In an electrically operated railway system the combination of a supply conductor divided into insulated sections, a plurality of direct-current generators for supplying energy thereto, means controlled by the current taken by the trains for varying the po tential of each of said generators, automatically operated switches controlled by the passage of the train for connecting and disconnecting said generators from the in sulated conductor sections and automatically operated switches also controlled by the passage of the train for selecting one of said generators to supply energy to each train during its passage over the whole of said insulated conductor sections.

8. In an electrically operated railway system the combination with a supply conductor divided into insulated sections, a plurality of generators for supplying energy to said sections, power operated switches controlled by the passage of the train for governing the connection and dlSCOIlIlGClLlOIl succeeding train passing thereovera 9. In an electrically operated railway sys tem the combination with a supply conductor divided into'insulated sections, a plurality of substations each having a plurality of generators for supplying energy to said sections, means controlled by the current taken by the train for varying the potential of each of the generators in said substations and means controlled by the passage. of the train for causing the potential of a generator in an adjacent substation to adjust itself automatically to that of the generator in the preceding substation supplying energy to the train.

In testimony whereof, I have hereunto subscribed my name this fourteenth day of June 1915.

CLIFFORD HUGH DOUGLAS.

Witnesses I A. S. COcHEWAILLE, EUs'rAcn H. BARKER.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, I). G. 

